EP1314487A2 - Coating process - Google Patents

Abstract

A process involves applying a material onto a substrate surface using an electrostatic charge. The substrate is located on a transport unit, and is electrostatically neutralized before it leaves the transport unit. The substrate is charged electrostatically before the material is applied by using an electrode, so the substrate is pressed against the transport unit. <??>A process involves applying a material onto a substrate surface using an electrostatic charge. The substrate is located on a transport unit, and is electrostatically neutralized before it leaves the transport unit. The substrate is charged electrostatically before the material is applied by using an electrode, so the substrate is pressed against the transport unit. The application unit consists of a nozzle, especially a wide slit nozzle, multi-channel nozzle or adapter nozzle. The transport unit voltage is 1-40 kV, especially 2-15 kV, and the substrate electrode consists of one or more individual electrodes. The material that is applied to the substrate consists of acrylate, natural rubber, synthetic rubber or EVA adhesive.

Description

The invention relates to a method for producing web-shaped, at least two-layered Products, especially adhesive tapes with a carrier material on which an adhesive is applied.

It has been working for a long time to make tapes without the use of solvents to manufacture or at least the coating process and the subsequent steps to be solvent-free. Corresponding products with adhesive layers based on Synthetic rubbers are known. However, these products only cover the lower performance range from adhesive tapes.

For some years now, solvent-free adhesives based on acrylate have also been available can be processed as a hot melt adhesive for adhesive tapes. Achieve this Usually, however, not the shear strengths such as acrylics, which in Solvent can be coated. A major reason for this is that the viscosity the masses during processing must not be too high, otherwise the melting and coating on a carrier is too expensive from an economic point of view is. The viscosity is largely determined by the molecular length. Shorter chain molecules however, require poorer shear strengths. Even with a network of the adhesive after coating, only a limited improvement is possible.

With natural rubber adhesive systems, melting can be avoided if it is succeeds in mixing the components of the mass without solvent, and if you have the feeds hot mass directly to a coating system. Coming as mixing units for example extruder in question. When mixing, the rubber is only allowed to do a little be broken down, otherwise the product properties will be impaired.

In the case of acrylate systems, melting can be avoided by using solvents or masses polymerized in water inline for coating the solvent or drains water. For example, solvents or water can be vacuumed Extract in a suitable extruder.

Wide slot slit nozzles are suitable for coating highly viscous materials. It shows that it is also suitable for highly viscous adhesive compositions as described above are. However, from a relatively low web speed, air bubbles between the adhesive and the substrate to be coated, which is typically based on a support roller is coated, included.

To reduce the formation of bubbles for the above task are on the market Blow nozzles, suction nozzles and so-called vacuum boxes recommended and offered. With with their help, the pressure force of the mass against the substrate should be increased.

From the film production (for example EP 0 920 973 A2) are wire, knife and Needle electrodes, which are arranged transversely to the web, are known with which electrical Loads are brought to the mass to be applied. This will make the mass through electrostatic forces pressed against a metal roller. Combinations are also used of electrostatic forces and forces caused by air movement (EP 0 707 940 A2).

In the literature, the coating of substrates described above is complex Solutions specified in which the substrate before placing on the chill roll charged in multi-stage preliminary processes, partially discharged by heating and is cooled in order to ultimately charge the substrate uniformly on the lay-on roller to obtain (for example EP 0 299 492 A2).

However, the maximum amount of charge on the substrate is relatively small because it is already reduced when leaving the charging roller until the from the Charge density resulting electrical field strength no longer ionization of the air takes place.

A roll insulation is known from film production (see, for example, US Pat. No. 4,997,600 A1) in which electrical charges are applied to the insulator layer before the film is placed in order to increase the pressure forces when the film is placed on the roll.
If no charges are applied to the insulated roller, electrostatic contact forces are greatly weakened as the insulator layer increases in thickness. With the required insulator thicknesses, which are necessary for the ceramic coatings specified here for sufficient high voltage strength, achievable bubble-free coating speeds are drastically reduced.

• auf eine rotierende Walze das Haftklebesystem in einer oder mehreren Lagen mittels eines Klebstoffauftragswerks aufgebracht wird,
• das auf der Walze befindliche Haftklebesystem in einer Bestrahlungsvorrichtung durch energiereiche Strahlung, und zwar mit Hilfe von Elektronenstrahlen (ES), UVoder IR-Strahlen, vernetzt wird und
• an die Walze das Substrat herangeführt wird, so daß das Haftklebesystem von der Walze auf das Substrat transferiert wird und gegebenenfalls aufgerollt wird.

DE 199 05 935 A1 discloses a method for producing a coating of solvent-free PSA systems, in particular on release-coated substrates, wherein

• the pressure-sensitive adhesive system is applied to a rotating roller in one or more layers by means of an adhesive applicator,
• the pressure-sensitive adhesive system located on the roller is cross-linked in a radiation device by high-energy radiation, with the aid of electron beams (ES), UV or IR rays, and
• the substrate is brought up to the roller so that the pressure-sensitive adhesive system is transferred from the roller to the substrate and is optionally rolled up.

• auf eine rotierende Walze mittels eines Fluidauftragswerk ein Fluidfilm aufgetragen wird,
• auf den Fluidfilm das Haftklebesystem in einer oder mehreren Lagen mittels eines Klebstoffauftragswerks aufgebracht wird, so daß sich der Fluidfilm zwischen Walze und Haftklebesystem befindet, und
• an die Walze das Substrat herangeführt wird, so daß das Haftklebesystem von der Walze auf das Substrat (releasebeschichtete und nicht releasebeschichtete) transferiert wird.

Typical radiation devices that are used in the embodiment of the method shown there are linear cathode systems, scanner systems or multi-longitudinal cathode systems, provided that they are electron beam accelerators.
The acceleration voltages are in the range between 40 kV and 350 kV, preferably 80 kV to 300 kV. The dose rates range between 5 to 150 kGy, in particular 20 to 90 kGy.
In particular, two medium pressure mercury lamps each with a power of 120 W / cm or one medium pressure mercury lamp with a power of 240 W / cm can be used as UV crosslinking systems. 10 to 300 mJ / cm ² are preferably set as doses.
DE 199 05 935 A1 describes a method for producing a coating of solvent-free PSA systems on, in particular, release-coated substrates, wherein

• a fluid film is applied to a rotating roller by means of a fluid applicator,
• the pressure-sensitive adhesive system is applied to the fluid film in one or more layers by means of an adhesive application unit, so that the fluid film is located between the roller and the pressure-sensitive adhesive system, and
• the substrate is brought up to the roller so that the pressure-sensitive adhesive system is transferred from the roller to the substrate (release-coated and non-release-coated).

The substrate is brought in in particular via a second roller. Papers, foils, nonwovens and release-coated materials such as release papers, foils and the like are used as substrates.
The second roller, also referred to as the contact roller, can be provided with a rubber coating and is preferably pressed against the roller with a line pressure of 50 to 500 N / mm, in particular with 100 to 200 N / mm. The contact roller preferably has a Shore hardness (A) of 40 to 100, in particular a Shore hardness of 60 to 80 shore (A).
The substrate is preferably fed to the roller in such a way that the speed of the roller surface coincides with that of the substrate. However, if the aim is to reduce the thickness of the adhesive film, the substrate can also have a higher speed.

In an advantageous embodiment, the roller is a steel roller, a chrome-plated steel roller, a rubber roller or a silicone rubber roller and / or the roller is made of elastic material. Furthermore, the roller can be smooth or have a slightly structured surface.
The smooth roller can preferably have a chrome layer. The chrome-plated steel roller can optionally have a highly polished surface with a roughness depth R _z <0.02 µm.
The coating roller can, however, also be rubberized, preferably with a rubber hardness of 40 to 100 shore (A), in particular with a hardness of 60 to 80 shore (A). According to the state of the art, the roller cover can consist of EPDM, Viton or silicone rubber or other elastic materials.

It is also found to be advantageous if the roller can be tempered, specifically preferably in a range from -10 ° C to 200 ° C, in particular from 2 ° C to 50 ° C.

• keine Blasen zwischen der Masseschicht und dem Substrat eingeschlossen werden,
• keine Eigenschaften des herzustellenden Produktes qualitätsbestimmend beeinträchtigt werden,
• keine Gefährdungen für das Bedienungspersonal entstehen.

The object of the invention is to enable the coating of in particular highly viscous compositions, such as are used for the production of adhesive tapes or similar products, with the preferred use of a slot die on a substrate at sufficiently high web speeds.
In doing so

• no bubbles are trapped between the ground layer and the substrate,
• no properties of the product to be manufactured are impaired in terms of quality,
• there are no hazards for the operating personnel.

This problem is solved by a method as set out in the main claim is. The subclaims describe advantageous embodiments of the method.

Accordingly, the invention relates to a method for producing web-shaped, at least two-layer products, in which one from an application device emerging mass as a layer with the application of electrostatic charges web-shaped substrate is applied, which is guided on a transport device and in which the substrate coated with the mass before leaving the Transport device is electrostatically neutralized, being on the web-shaped substrate before coating by means of a substrate electrode, electrostatic charges are applied be so that the substrate is pressed onto the transport device.

In a first preferred embodiment of the method, the application device is as Nozzle, in particular a wide slot nozzle, a two- or multi-channel nozzle or an adapter nozzle.

The transport device is preferred with the mass emerging from the nozzle non-contact coated. The distance from the nozzle to the transport device can preferably be Amount to 0.01 to 60 mm, in particular 1 to 30 mm.

More preferably, the transport device is designed as a lay-on roller, which further is in particular grounded and / or temperature-controlled, preferably in a range from -10 ° C to 200 ° C, very particularly preferably in a range from 0 ° C to 180 ° C, especially from 2 ° C to 50 ° C.

In order to be able to provide the mass with the charge according to the invention, the mass can be electrostatically charged by means of at least one charging electrode, hereinafter referred to as the placement electrode, which is located above the transport device, preferably the lay-on roller, in the region of the support line of the mass layer. The layer is pressed onto the substrate with the aid of the charges.
The application electrode is used to apply charges to the mass on one side. Counter-charges appear immediately on the surface of the transport device, preferably a lay-on roller. From the resulting field, a force acts on the mass plus substrate, which presses both layers onto the transport device, preferably a lay-on roller.

Furthermore, it is an excellent embodiment of the inventive concept if the substrate coated with the composition is electrostatically neutralized by means of at least one counter-charge electrode before leaving the transport device, preferably a lay-on roller, the counter-charge electrode being particularly in the area above the transport device, preferably a lay-on roller between the support line of the ground layer and the peel line of the coated substrate.
Thus, electrostatic discharges, as a result of the application of charges by the application electrode, by the application of counter-charges with reversed polarity and suitable strength, can be avoided even before leaving the coated substrate by the preferred application roller.

For fine adjustment, it is also advantageous to use the coated line above the peel line Attach an active discharge device to the substrate from the preferred lay-on roller, to fluctuations in the process over time and the width of the Compensate for the web.

The counter charge electrode is preferably in the form of a “wire”, “knife” and / or "Needle electrode" executed, which is arranged transversely to the web.

Without sufficient neutralization of the electrical charges applied to the web by the application electrode (s), a corona discharge can occur between the application roller and the underside of the substrate, which particularly affects the anti-adhesive properties of the substrate.
In addition, the corona discharge transports charges of opposite polarity to the underside of the web as on the coating side. If one then neutralizes such a path with conventional active or passive discharge devices, the measurable electric field is eliminated, but there are always very strong, equally high charges of opposite polarity on both sides. If the electrical conductivity of the layers between the charges is low, uncontrollable discharges can occur in the wrapped bales.

Then, in order to stress the substrate as little as possible, the substrate should be placed on the transport device, preferably lay-on roll, with a pressure roller and / or removed from the transport device, preferably lay-on roll with a removal roll.
It is also advantageous to choose a conductive elastic coating for the preferred pressure roller with which the substrate is placed on the preferably selected lay-on roller. If a conductive coating cannot be used for process reasons, it is advantageous to electrostatically discharge the roller shell in an area in which it is not covered by the substrate. Otherwise, the roller surface can absorb more electrical charges with each revolution until uncontrolled discharge phenomena occur.

It is also advantageous to have a panel made of electrically insulating material in the direction of web travel to be placed in front of the placement electrode, whereby the ion-enriched Space in the area of the placement electrode to the nozzle side is limited. It is cheap additionally an earthed one on the side of the screen facing away from the placement electrode attach electrically conductive sheet. A corona discharge can be prevented with the aperture the lay line through the mass layer on the substrate can be significantly reduced.

An arrangement is also advantageous in which not only a needle electrode is used as a placement electrode is used, but two in the web direction directly one behind the other and at the the two electrodes are laterally offset by half a needle spacing, whereby the Ability of the needle electrodes to high charging currents with a relatively uniform Charge distribution is paired. The front electrode has been shown to be advantageous with a smaller high voltage than the rear one.

In a further preferred embodiment of the invention, the substrate before Coating electrostatically neutralized.

To further exclude the known disadvantages of the prior art, the electrical voltage of the transport device, preferably lay-on roller, 1 to 40 kV, in particular 2 to 15 kV.

In a further preferred variant of the method according to the invention, the Mass on the substrate before leaving the transport device, preferably lay-on roller, cross-linked or polymerized, in particular by means of electron beams, UV rays, visible light or a combination thereof and / or thermal.

In a further preferred embodiment of the invention, the substrate electrode formed from several electrodes, preferably needle, knife or wire electrodes, which are arranged one behind the other.

Further preferred is the substrate electrode between the pressure roller and the application device arranged.

It is very advantageous to place the substrate electrode in the area instead of a pressure roller the support line of the substrate on the transport device, preferably lay-on roller, to arrange.

Finally, the substrate electrode can advantageously with an electrical voltage of the opposite polarity as the application electrode, the The level of the voltage to be applied is selected independently of the level of the voltage can be, which is due to the placement electrode.

It is also advantageous if the transport device with an electrically insulating Cover is provided.

In a further preferred embodiment of the method, the thickness of the coating is thinner than 300 µm, especially between 20 and 200 µm, especially between 20 and 120 µm thick and / or soft on the entire surface in contact with the substrate the transport device preferably not more than ± 20% from the mean, in particular not more than ± 5%.

It is also very advantageous if the coating has a low roughness and / or anti-adhesive Has properties.

It is particularly advantageous to cover the area in which it is not covered by the Substrate is covered, neutralize electrostatically. Otherwise this can be done with everyone Revolution take up more electric charges until uncontrolled discharge phenomena occur. But even small uncontrolled charges, especially if they are uneven, they have a negative impact on blistering between coating and substrate.

In an excellent embodiment, the cover consists of polyester, teflon, Kapton, silicone rubber, polypropylene, casting resin or other materials with sufficient High voltage resistance with a low layer thickness.

For example, a shrink tube can be used as a covering, which in particular a lay-on roller, pulled and shrunk, can be used.

Also an electrically conductive sleeve sleeve coated with an insulator, which over the is pulled over the transport device, in particular lay-on roller, is suitable in excellent way.

In a preferred variant of the process, the coating is applied in excess, is cured if necessary, furthermore this is in the following except for one desired very constant layer thickness removed and finally for a low roughness polished.

Examples of possible embodiments of the coating are of different thicknesses PET films called, further cast resin applications preferably with thicknesses between 20 µm and 300 µm, especially with thicknesses between 20 µm and 120 µm.

Another preferred variant is one covered with an electrical insulator is an electrically conductive conveyor belt on which the substrate for coating a lay-on roller is guided, the coating preferably having a thickness between 20 µm and 300 µm and in particular thicknesses between 20 µm and 120 µm.

Also a thin conveyor belt made of an electrical insulator, preferably with Thicknesses between 20 µm and 300 µm and in particular with thicknesses between 20 µm and 120 µm, on which the substrate for coating is guided over a lay-on roller, represents preferred variant.

Another preferred variant is a modification in which an auxiliary film, the after unwinding a bale between the electrically conductive transport device and the substrate is brought after peeling off the coated substrate is wrapped back into a bale from the auxiliary film.

The method can be used excellently in applications in which the Substrate is a carrier material for an adhesive tape and / or the mass is an adhesive.

In this case, acrylic, natural rubber, Synthetic rubber or EVA adhesives.

The method can also be used excellently in applications, if the substrate is a release liner for an adhesive tape and the mass is an adhesive is.

The method can also be used excellently in applications, if the substrate is a preliminary product consisting of release liner, adhesive and carrier, or is a double-sided adhesive tape and the mass is an adhesive

It also shows that the tendency to bubble between the mass and the Substrate increases when the substrate is placed on the lay-on roller charged uncontrollably. It is also problematic when electrostatic discharge devices not be attached to the side of the web on which charges can take place through separation processes. In this case too no more electric field measured outside, but still located on both sides electric charges of equal polarity with opposite polarity. The height these double loads typically fluctuate in the web direction and also across Train. These undefined double loads effectively reduce them in a production process maximum safe web speed.

In an advantageous embodiment, discharge devices are always on the Side attached, on which charges arise through separation processes. With electrostatic difficult substrates, it can be advantageous in extreme cases, behind each deflection roller suitable discharge devices on the contact side and already in the winding nip during processing to install.

It is also advantageous to pre-process the delivered bale with the substrate drive electrostatically controlled, or the interim storage time due to sufficient electrical residual conductivities large enough to allow double charges to flow together to choose. The time required can also be achieved by storing at elevated temperatures be shortened.

It is particularly advantageous in the web running direction between the application device and the Application electrode to attach a panel made of electrically insulating material, whereby the space filled with ions in the area of the application electrode of the application device, in particular nozzle, the transport device, in particular lay-on roller, and the Aperture is limited.

The coating can also consist of one or more views and / or the substrate consist of one or more layers, it being advantageous to use multilayered layers Produce coatings with multi-channel or adapter nozzles.

It is also very advantageous when using adapters with a single-channel nozzle or with a three-channel nozzle a coating consisting of a first adhesive, a Carrier and a second adhesive, and the substrate is a release liner is.

Unexpectedly for the person skilled in the art, the inventive method offers a solution for the tasks. This is how a coating with a slot die is applied to a substrate at sufficiently high web speeds without bubbles between the ground layer and the substrate arise without further properties of the product to be manufactured are impaired in terms of quality and without there are special dangers for the operating personnel.

Surprisingly, it has been shown that bubbles between the mass layer and the Substrate are formed especially when there is air between the substrate and the lay-on waize is located. With bias-free placement of the substrate on the lay-on roller could be coated at a higher web speed without causing blistering came. The coating pattern is significantly more uniform than with one Coating in which the substrate is on the lay-on roller during the manufacturing process was not applied without bubbles.

Especially when placing sensitive substrates that only have low web tensions can be driven, with a pressure roller it is easy to Lifting (lapping) the substrate directly behind the rollers, so that there is again an air layer located between the substrate and the transport device.

A particularly good wetting of the transport device, preferably roller, with the Substrate with low air inclusions can be reached if the substrate with a Substrate electrode, instead of a pressure roller, in the area above the support line of the Substrate is pressed. Good wetting, that is, almost complete squeezing out the air, is conveyed even further by a very smooth roller surface.

In addition, it has also been shown that an antiadhesive release layer on the Side facing the transport device less due to the loading and unloading processes is damaged if the wetting on the transport device is better.

The existing gas space (volume of the bubbles between the substrate and the transport device in the area of charging electrodes) in which one is harmful to the release layer Ionization, especially due to the high electrical fields of the ground electrode, can take place, decreases with the quality of the wetting of the transport device, preferably lay-on roller.

Furthermore, it can be unexpectedly found that blistering between the Mass layer and the substrate is greatly reduced when electrostatic neutralization of the substrate in the web area in front of the lay-on roller, and very much so preferably on the side on which there is a charge separation Charge accumulation is coming.

More preferably, that can be between the placement electrode and discharge electrode substrate located on the transport device by means of irradiation device high-energy radiation, with the help of electron beams (ES), UV or IR rays, be networked. This is particularly advantageous if it is Substrate is an adhesive.

Typical radiation devices, which in the inventive design of the Linear cathode systems, scanner systems are used for the process or multi-longitudinal cathode systems, provided that they are electron beam accelerators is.

The acceleration voltages are preferably in the range between 40 kV and 500 kV, in particular between 80 kV and 300 kV. The dose rates range between 5 to 150 kGy, in particular 15 to 90 kGy.
One or more medium-pressure mercury lamps with an output of up to 240 W / cm each can be used as UV crosslinking systems. 10 to 300 mJ / cm ² are preferably set as doses.

Halogen lamps, in particular, can be used for crosslinking or polymerization with visible light are used.

Release liners with anti-adhesive coatings can also be used as substrates Adhesives stick little, are used. The carrier materials of release liners typically consist of paper or plastics, such as PET, PP or PE. The plastics used generally have good electrical properties Isolation properties and high electrical breakdown field strengths.

In the case of paper, however, the electrical properties are significantly affected by thin anti-adhesive coating, but also due to the impregnation and moisture content, certainly. When applying the mass with the help of electrostatic Charging gives the electrical properties of the applied mass a stronger one Meaning too. Although electrical insulators are mostly used as masses, they often already have one at typical coating temperatures of 100 ° C and more residual conductivity so high that part of the charges applied by the mass and the paper used as a release liner flow into the lay-on roller before the roller is left. Because on the lay-up line with not too high electrical conductivity practically all charges are still on the ground layer, are still sufficient high pressure forces can be achieved for a bubble-free coating. In the subsequent electrical neutralization by applying counter-charges is necessary note that some of the loads have already drained away. At low web speeds is the time available for the charges to drain larger, and proportionately more charges flow off before reaching the detachment line. The The optimal amount of counter-charges depends on the speed of the web.

For economic reasons, but also for procedural reasons, release liners that are as thin as possible are used for release liners. So-called "undercoating coatings" are often also used. This means that the carrier is not 100% covered by the release coating. It has been shown that in the case of such release liners, the coated substrate must be neutralized much more precisely than, for example, in the case of PET or PP films with completely covering silicone coatings of 1.5 g / m ² and more.

In the case of double-sided adhesive tapes, a distinction is made between the open and the covered Side of the release liner. The covered side of the release liner is after unwinding from the roll with the composite of first adhesive layer, carrier and second adhesive layer covered. For trouble-free further processing after Coating up to application should the release forces from the adhesive on the open less than or equal to, but at least not significantly greater than the separating forces be on the covered side, otherwise it will be used to reorient the release liner other side can come.

Graded release liners are also available. They can be used to ensure that the covered side has significantly higher separating forces.
In particular, in the case of non-graded release liners, damage to the open side when producing a double-sided adhesive tape may only be relatively minor if one wishes to avoid an exchange for an undamaged release liner.

For the production of double-sided adhesive tapes, the substrate can also be made from the preliminary product from the first step, namely from a release liner, an adhesive layer and the carrier.

All known textile supports such as woven fabrics, knitted fabrics, scrims or nonwovens can furthermore be used as substrate or support material, "fleece" being understood to mean at least textile fabrics according to EN 29092 (1988) as well as stitchbonded nonwovens and similar systems.
Spacer fabrics and knitted fabrics with lamination can also be used. Spacer fabrics of this type are disclosed in EP 0 071 212 B1. Spacer fabrics are mat-shaped laminates with a cover layer made of a fiber or filament fleece, an underlayer and individual or tufts of holding fibers between these layers, which are needled over the surface of the laminate and are needled through the particle layer and connect the cover layer and the underlayer to one another. According to EP 0 071 212 B1, particles of inert rock particles, such as sand, gravel or the like, are present in the holding fibers as an additional but not necessary feature.
The holding fibers needled through the particle layer keep the cover layer and the underlay layer at a distance from one another and they are connected to the cover layer and the underlay layer.
Spacer fabrics or knitted fabrics are described, inter alia, in two articles, namely an article from the specialist journal "ketten Wirk-praxis 3/93", 1993, pages 59 to 63
"Raschel knitted spacer fabrics" and
an article from the specialist journal "ketten Wirk-praxis 1/94", 1994, pages 73 to 76
"Raschel knitted spacer fabrics"
the content of which is hereby incorporated by reference and the content of which forms part of this disclosure and invention.

Knitted fabrics are textile fabrics made from one or more threads or thread systems through stitch formation (thread grinding), in contrast to woven goods (Fabrics), in which the surface is crossed by crossing two thread systems (warp and Wefts) is produced and the nonwovens (fiber composites), in which a loose fiber pile solidified by heat, needling, sewing or by water jets becomes.

Knitted fabrics can be knitted in which the threads cross through the Run textile, and divide it into knitted fabrics in which the threads run lengthways through the textile. Because of their knitted structure, knitted fabrics are in principle flexible, cuddly Textiles because the stitches can stretch in length and width and the endeavor have to return to their starting position. They are very high quality material durable.

The nonwovens used are particularly solidified staple fiber nonwovens, but also filament, Meltblown and spunbonded nonwovens, which usually have to be additionally consolidated. As possible For nonwovens, consolidation methods are mechanical, thermal and chemical solidification known. During mechanical strengthening, the fibers mostly by swirling the individual fibers, by meshing fiber bundles or mechanically held together by sewing in additional threads, so leave adhesive by thermal as well as chemical processes (with binder) or achieve cohesive (binder-free) fiber-fiber bonds. These can be suitable formulation and process control exclusively or at least predominantly Restrict to fiber nodes so that the loose, open structure is retained a stable, three-dimensional network is nevertheless formed in the fleece.

Nonwovens have proven to be particularly advantageous, in particular by overstitching are solidified with separate threads or by stitching.

Solidified nonwovens of this type are produced, for example, on sewing-knitting machines of the "Malivlies" type from Karl Meyer, formerly Malimo, and can be obtained, inter alia, from Naue Fasertechnik and Techtex GmbH. A Mali fleece is characterized in that a cross fiber fleece is consolidated by the formation of stitches from fibers of the fleece.
A fleece of the type Kunitvlies or Multiknitvlies can also be used as a carrier. A Kunitvlies is characterized in that it results from the processing of a longitudinally oriented nonwoven fabric to a flat structure, which has loops on one side and mesh webs on the other side or poly fiber folds, but has neither threads nor prefabricated flat structures. Such a fleece has also been produced for a long time, for example, on sewing-knitting machines of the "Kunitvlies" type from Karl Mayer. Another characteristic feature of this fleece is that it can absorb high tensile forces in the longitudinal direction as a longitudinal fiber fleece. A multi-knit fleece is characterized in comparison to the Kunit fleece in that the fleece is strengthened by both-sided piercing with needles both on the top and on the bottom.
Finally, nonwovens are also suitable as a preliminary product to form an adhesive tape. A sewing fleece is formed from a fleece material with a plurality of seams running parallel to one another. These seams are created by sewing or sewing continuous textile threads. Sewing-knitting machines of the "Maliwatt" type from Karl Mayer, formerly Malimo, are known for this type of fleece.

Also particularly advantageous is a staple fiber fleece that is pre-consolidated by mechanical processing in the first step or that is a wet fleece that has been laid hydrodynamically, wherein between 2% and 50% of the fibers of the fleece are melt fibers, in particular between 5% and 40% of the fibers of the fleece.
Such a fleece is characterized in that the fibers are laid wet or, for example, a staple fiber fleece is pre-consolidated by forming stitches from fibers of the fleece or by needling, sewing or air and / or water jet processing.
In a second step, heat setting takes place, the strength of the fleece being increased again by melting or melting on the melt fibers.
The nonwoven backing can also be solidified without a binder, for example by hot stamping with structured rollers, properties such as strength, thickness, density, flexibility and the like being applied via pressure, temperature, residence time and the stamping geometry. can be controlled.

Adhesive bonding of mechanical is particularly important for the use of nonwovens Pre-consolidated or wet-laid nonwovens of interest, these by adding Binder can be made in solid, liquid, foamed or pasty form. principal Dosage forms are possible in many ways, for example solid binders as powder for trickling, as a film or as a grid or in the form of binding fibers. liquid Binders can be applied dissolved in water or organic solvents or as a dispersion. Binding dispersions are mainly chosen for adhesive bonding: Thermosets in the form of phenolic or melamine resin dispersions, elastomers as dispersions natural or synthetic rubbers or mostly dispersions of thermoplastics such as acrylates, vinyl acetates, polyurethanes, styrene-butadiene systems, PVC and the like. and their copolymers. Usually these are anionic or non-ionic Stabilized dispersions, but in special cases also cationic dispersions be an advantage.

The type of binder can be applied according to the prior art and is for example in standard works of coating or nonwoven technology such as "nonwovens" (Georg Thieme Verlag, Stuttgart, 1982) or "Textile Technology Nonwovens Production" (Employers' group overall textile, Eschborn, 1996).

For mechanically pre-consolidated nonwovens that already have sufficient bond strength, one-sided spray application of a binder is recommended in order to specifically change surface properties.
In addition to the economical use of the binding agent, the energy required for drying is also significantly reduced in this way. Since no squeeze rollers are required and the dispersions predominantly remain in the upper area of the nonwoven, undesirable hardening and stiffening of the nonwoven can be largely prevented. For adequate adhesive bonding of the nonwoven backing, binders of the order of 1% to 50%, in particular 3% to 20%, based on the weight of the nonwoven, are generally to be added.

The addition of the binder can already during the manufacture of the fleece, in the mechanical Pre-consolidation or in a separate process step, this inline or can be done off-line. After the binder has been added it must be temporary a state is created for the binder in which it becomes sticky and adhesive connects the fibers - this can occur during drying, for example of dispersions, but can also be achieved by heating, using flat or partial pressure further variation possibilities are given. Activation of the binder can also be used in known drying tunnels, but with a suitable binder selection by means of infrared radiation, UV radiation, ultrasound, high-frequency radiation or the like respectively. For the later end use, it makes sense, but is not absolutely necessary, that the binder becomes tacky at the end of the nonwoven manufacturing process has lost. It is advantageous that volatile components by thermal treatment how fiber auxiliaries are removed and thus a fleece with favorable fogging values arises so that when using a low-fogging adhesive a tape with special favorable fogging values can be produced.

Another special form of adhesive bonding is that activation of the binder by dissolving or swelling. In principle, you can also do this the fibers themselves or mixed special fibers take over the function of the binder. As such solvents for most polymeric fibers from an environmental point of view are questionable or problematic in their handling, this method is rarely used.

In particular, polyester, polypropylene, Viscose or cotton fibers are provided. The selection is not based on that mentioned materials, but it can be recognized by the expert without having to be inventive, a multitude of other fibers for production of the fleece can be used.

Laminates and nets are also used in particular as carrier materials, but also foils (for example a polyolefin from the group of polyethylenes (for example HDPE, LDPE, MDPE, LLDPE, VLLDPE, copolymers of ethylene with polar Comonomers) and / or the group of polypropylenes (for example polypropylene homopolymers, Polypropylene random copolymers or polypropylene block copolymers), mono- or biaxially oriented polypropylene, polyester, PVC, PET, polystyrene, Polyamide or polyimide), foams, foam, for example made of polyethylene and Polyurethane, foamed foils and creped and uncreped papers. Can continue these materials are pretreated or post-treated. Common pre-treatments are corona radiation, impregnation, coating, painting and waterproofing; Common post-treatments are calendering, tempering, laminating, punching and Stock up.

A low flammability of the backing material and the entire adhesive tape leaves achieve by adding flame retardants to the carrier and / or the adhesive become. These can be organic bromine compounds, if necessary with synergists like antimony trioxide, but with regard to the halogen-free nature of the adhesive tape red phosphorus, organophosphorus, mineral or intumescent compounds such as ammonium polyphosphate alone or in combination with synergists is preferred Find.

Essentially all known adhesives with a sufficiently high adhesive strength can be used as adhesive on the adhesive base to be packaged.
The adhesive of the adhesive tape can consist of an adhesive based on solvent-based natural rubber and acrylate adhesives. Adhesives based on acrylate dispersions are preferred; adhesives based on styrene-isoprene-styrene block copolymers are particularly preferred. These adhesive technologies are known and are used in the adhesive tape industry.

The amount of adhesive applied to the backing material is preferably 15 to 60 g / sqm. In a further preferred embodiment, the layer application is from 20 to 30 g / qm set.

The adhesive tapes can be produced by known processes. An overview The usual manufacturing processes can be found, for example, in "Coating Equipment", Donatas Satas in Handbook of Pressure Sensitive Adhesive Technology, second edition, edited by Donatas Satas, Van Nostrand Reinhold New York pp. 767-808. The known methods for drying and cutting the tapes are also in the Handbook of Pressure Sensitive Adhesive Technology, page 809-874.

An adhesive based on an acrylate hotmelt is suitable which has a K value of at least 20, in particular greater than 30 (measured in each case in a 1% strength by weight solution in toluene, 25 ° C.), obtainable by concentrating a solution of such Mass to a system that can be processed as a hot melt.
Concentration can take place in suitably equipped kettles or extruders, particularly in the case of the associated degassing, a degassing extruder is preferred.
Such an adhesive is set out in DE 43 13 008 C2. In an intermediate step, the solvent is completely removed from these acrylic masses produced in this way.

The K value is determined in particular in analogy to DIN 53 726.

In addition, other volatile components are removed. After coating from the melt, these masses have only a small amount of volatile Ingredients. Thus, all monomers / formulations claimed in the above-mentioned patent can be taken over. Another advantage of those described in the patent Masses can be seen in the fact that these have a high K value and thus a high molecular weight exhibit. The skilled worker is aware that systems with higher molecular weights Network more efficiently. The proportion therefore drops accordingly volatile components.

The solution of the mass can 5 to 80 wt .-%, in particular 30 to 70 wt .-% Contain solvents.

Commercial solvents are preferably used, especially low boiling hydrocarbons, ketones, alcohols and / or esters.

Single-screw, twin-screw or multi-screw extruders are further preferred used with one or in particular two or more degassing units.

Benzoin derivatives can be polymerized into the acrylic hotmelt-based adhesive be, for example, benzoin acrylate or benzoin methacrylate, acrylic acid or methacrylic acid esters. Such benzoin derivatives are described in EP 0 578 151 A.

The acrylic hot melt adhesive can be UV crosslinked. Other types of networking are also possible, for example electron beam crosslinking.

In a particularly preferred embodiment, copolymers are used as self-adhesive compositions from (meth) acrylic acid and its esters with 1 to 25 carbon atoms, maleic, Fumaric and / or itaconic acid and / or their esters, substituted (meth) acrylamides, Maleic anhydride and other vinyl compounds such as vinyl esters in particular Vinyl acetate, vinyl alcohols and / or vinyl ethers used.

The residual solvent content should be less than 1% by weight.

Furthermore, an adhesive can be used, from the group of natural rubbers or the synthetic rubbers or from any blend of natural rubbers and / or synthetic rubbers, the natural rubber or Natural rubbers basically of all available qualities such as crepe, RSS, ADS, TSR or CV types, depending on the required level of purity and viscosity, and the synthetic rubber or the synthetic rubbers from the group of the statistical copolymerized styrene-butadiene rubbers (SBR), the butadiene rubbers (BR), the synthetic polyisoprene (IR), butyl rubber (IIR), halogenated butyl rubber (XIIR), acrylic rubbers (ACM), ethylene-vinyl acetate copolymers (EVA) and the polyurethanes and / or their blends can be selected.

It is further preferred to add thermoplastic elastomers with a weight fraction of 10 to 50% by weight to the rubbers to improve the processability, based on the total elastomer fraction.
The particularly compatible styrene-isoprene-styrene (SIS) and styrene-butadiene-styrene (SBS) types should be mentioned here as representative.

Tackifying resins are, without exception, all known and in the literature described adhesive resins can be used. The rosins are representative, their disproportionated, hydrogenated, polymerized, esterified derivatives and salts, the aliphatic and aromatic hydrocarbon resins, terpene resins and terpene phenolic resins. Any combination of these and other resins can be used to adjust the properties of the resulting adhesive as desired. On the presentation of the state of knowledge in the "Handbook of Pressure Sensitive Adhesive Technology "by Donatas Satas (van Nostrand, 1989) is expressly pointed out.

Hydrocarbon resin is a collective name for thermoplastic, colorless to intensely brown colored polymers with a molecular weight of generally <2000.

They can be divided into three large groups according to their provenance: in petroleum, Coal tar and terpene resins. The most important coal tar resins are the coumarone indene resins. The hydrocarbon resins are made by polymerizing the raw materials isolatable unsaturated compounds obtained.

The hydrocarbon resins also include polymers with a correspondingly low molar mass which are accessible by polymerizing monomers such as styrene or by polycondensation (certain formaldehyde resins). Hydrocarbon resins are products with a softening range that varies within a wide range from <0 ° C (liquid hydrocarbon resins at 20 ° C) to> 200 ° C and a density of approx. 0.9 to 1.2 g / cm ³ .

They are soluble in organic solvents such as ethers, esters, ketones and chlorinated Hydrocarbons, insoluble in alcohols and water.

Rosin is a natural resin that is made from the raw resin of Conifers is obtained. There are three types of rosin: Balsam resin as Distillation residue of turpentine oil, root resin as an extract from coniferous rhizomes and tall resin, the distillation residue from tall oil. The largest in terms of quantity Balsam resin is important.

Rosin is a brittle, transparent product from red to brown in color. It is insoluble in water, but soluble in many organic solvents such as (chlorinated) aliphatic and aromatic hydrocarbons, esters, ethers and ketones as well in vegetable and mineral oils. The softening point of rosin is in the Range from approx. 70 to 80 ° C.

Rosin is a mixture of approx. 90% resin acids and 10% neutral substances (fatty acid esters, terpene alcohols and hydrocarbons). The most important rosin resin acids are unsaturated carboxylic acids of the gross formula C20H3002, abietic, neoabietic, levopimaric, pimaric, isopimaric and palustric acids, in addition to hydrogenated and dehydrated abietic acid.
The proportions of these acids vary depending on the provenance of the rosin.

All plasticizers known from adhesive tape technology can be used as plasticizers Substances are used. These include the paraffinic and naphthenic oils, (functionalized) oligomers such as oligobutadienes, isoprene, liquid Nitrile rubbers, liquid terpene resins, vegetable and animal oils and fats, phthalates, functionalized acrylates.

All are known for the purpose of thermally induced chemical crosslinking Thermally activated chemical crosslinkers such as accelerated sulfur or Sulfur donor systems, isocyanate systems, reactive melamine, formaldehyde and (optionally halogenated) phenol-formaldehyde resins or reactive phenolic resin or diisocyanate crosslinking systems with the corresponding activators, epoxidized Polyester and acrylate resins and their combinations can be used.

The crosslinkers are preferably activated at temperatures above 50 ° C., in particular at temperatures from 100 ° C. to 160 ° C., very particularly preferably at temperatures from 110 ° C. to 140 ° C.
The crosslinkers can also be thermally excited by IR rays or other high-energy electromagnetic alternating fields.

A particularly advantageous embodiment is shown on the basis of the figures described below of the invention explained in more detail without the choice of the figures shown want to limit unnecessarily.

Figur 1

das erfindungsgemäße Verfahren in-einer-besonders vorteilhaften Ausführungsformen sowie

Figur 2

das erfindungsgemäße Verfahren in einer weiteren besonders vorteilhaften Ausführungsform.

Show it

Figure 1

the inventive method in a particularly advantageous embodiments as well

Figure 2

the method according to the invention in a further particularly advantageous embodiment.

1 shows a device in which an adhesive 8 is placed on a substrate 7. It shows a process for the production of adhesive tapes.
The device has a lay-on roller 6, in which case an earthed cooling roller is used. The substrate 7 is a release liner, consisting of a monoaxially stretched polypropylene film which has been coated on both sides with anti-adhesive silicone layers.
The substrate 7 is placed on the lay-on roller 6 via a pressure roller 4, which removes the air between the substrate 7 and lay-on roller 6. The last remaining air between substrate 7 and lay-on roller 6 is then largely removed by means of a substrate electrode 10, which is located between the pressure roller 4 and the coating nozzle 5.

The mass 8, here an adhesive, is finally applied via the coating nozzle 5, which is carried out under the placement electrode 1.

With the application electrode 1, charges are applied to the mass 8 on one side. Counter-charges appear immediately on the surface of the lay-on roller 6. From the resulting field, a force acts on the mass plus the substrate, which presses both layers onto the lay-on roller 6.
After passing through the counter-charge electrode 2 and the discharge electrode 3, the substrate 7 coated with the mass 8 is removed from the lay-on roller 6. The counter-charge electrode 2 applies positive charges to the mass 8, the counter-charges previously present on the surface flow away again, the field largely collapses.
Finally, the last charges on the mass 8 are removed from the discharge electrode 3.

With the aperture 9 in front of the placement electrode 1, the space enriched with ions limited.

Figure 2 largely corresponds to Figure 1. The pressure roller 4 for placing the substrate 7 on the lay-on roller 6 is not present. Placing the substrate on the Lay-on roller 6 is done here by means of a substrate electrode 10 in the area above Support line of the substrate 7 on the lay-on roller 6, whereby the air between the substrate 7 and lay-on roller 6 is removed particularly effectively.

Examples example 1

An acrylate adhesive was polymerized in solvents and concentrated in an extruder. Resins, anti-aging agents and other additives were mixed in a further extruder. The mass was coated using a melt pump through a slot die (from Extrusion Dies Inc./USA), with a coating width of 35 cm, on a 70 μm thick polypropylene separating film, which was placed on a tempering lay-on roller with a pressure roller. A 50 µm thick BOPP film was laminated onto the coated side of this film, which was coated on both sides with 0.5 g / m ² strong anti-adhesive silicone layers. The laminate was then wound up. In this case, the lay-on roller was equipped with a conductive, very smooth, polished chrome layer.

A needle electrode was used as a loading electrode (type: R130A from Eltex) used by a high voltage generator (type KNH34 / N was supplied by Eltex). In addition, the same second needle electrode (Counter charge electrode) in the area between the ground contact line and the withdrawal line of the coated substrate attached by the lay-on roller and by one another high voltage generator (type KNH34 / P from Eltex) with high voltage of the opposite polarity. The lay-on electrode was at a web speed of 75 m / min with a negative high voltage of -15.8 kV. The distance of the needle tips from the roller surface, the position of the electrode in the direction of web travel and the angle of inclination of the electrode to the tangent of the lay-on roller were optimized until there were no more bubbles between the mass and the substrate were watching. The needle distance was approx. 5 mm from the roller surface, the position of the electrode was approx. 8 mm in the web running direction behind the lay line and the angle of inclination to the tangent of the lay-on roller was 90 °.

The counter charge electrode was charged with an opposite, ie positive, high voltage of +13.7 kV, so that the absolute value of the electrode current was equal to that of the application electrode and the coated substrate was thus electrostatically neutralized before leaving the roller. The distance between the needle tips of the counter charge electrode and the roller surface was approximately 12 mm.
However, an active discharge electrode (type R51A from Eltex) was additionally provided above the line of separation of the web from the lay-on roller, which was fed with 8 kV alternating current at a frequency of 50 Hz from a power supply unit (from Eltex type: ES52).

With a mass application of 50 g / m, a coating speed of 85 m / min reached without blowing between the mass and the substrate.

The blistering was determined on the one hand inline with a camcorder, a strong one Light source and a monitor with the help of still images at exposure times between 100 and 1000 microseconds and secondly by looking at patterns after stopping the train.

In the following, a charging electrode (substrate electrode) was attached in the area between the pressure roller and the coating device above the laying roller. The substrate electrode (type: R130A from Eltex) was applied with a positive high voltage of +8.7 kV. So it had the opposite polarity as the application electrode. The supply came from a high voltage generator (type KNH34 / P from Eltex). The distance between the needle tips of the counter charge electrode and the roller surface was approximately 12 mm.
Due to the positive charges applied to the substrate, the high voltage at the application electrode could be reduced to 9.2 kV. The high voltage at the counter charge electrode could also be reduced. Here, the high voltage was set so that the sum of the currents in the substrate electrode and in the counter charge electrode was equal to the absolute value of the current in the application electrode. This was followed by a fine adjustment so that only minimal charges were found on the coated substrate after leaving the lay-on roller.
With a mass application of 50 g / m, a coating speed of 92 m / min was achieved with this arrangement without the blowing between the mass and the substrate being observed.
In addition, it was observed that the tendency of the MOPP separating film to form folds, as a result of the heating due to the application of the hot mass, due to the firm adhesion to the lay-on roller, due to the charging with the substrate electrode, was significantly reduced.
As the web speed increased further, small bubbles between the coating and the substrate became apparent, which were arranged around circles of approximately 3-5 mm in diameter.

Example 2

It was assumed that the bubbles arranged in circles as described in Example 1 were caused by residual air remaining between the lay-on roller and the substrate. This was to be assumed, since the electric field under the application electrode is influenced by residual air bubbles. In addition, it is to be expected that the air in these residual air bubbles will be ionized, as a result of which, in addition to an even greater influence on the electrical field lines, damage to the release layer can also occur.
In this experiment, the same structure as in Example 1 was chosen. However, the path was changed so that the pressure roller was not wrapped around. Instead, the substrate was pressed against the lay-on roller with the substrate electrode, which was arranged above the support line. The same voltage settings as in Example 1 could be selected.
With the same mass application of 50 g / m as in Example 1, the maximum coating speed of 100 m / min was achieved with this arrangement without the blowing between the mass and the substrate being observed.
The small bubbles observed in Example 1 between the coating and the substrate, which were arranged around circles of approximately 3 to 5 mm, were no longer observed.
To compare the damage to the release layers, samples were also produced at 85 m / min and compared with the procedure in Example 1 with a pressure roller and without a substrate electrode.

The damage was determined using the following measurement method.

Measurement of the separation force

A double-sided test tape is applied to the side of the release liner to be measured applied bubble-free and pressed with a 2 kg steel roller by rolling it over five times. This is followed by storage for one week in a heat chamber at 70 ° C. The side facing away from the release liner is used to measure the pulling force (separating force) of the test tape fixed on a steel rail. Then the on the test tape glued release liner at an angle of 180 ° at a speed deducted from 300 mm / min. The required tensile force (in cN / cm) is at one Tensile testing machine under standardized conditions (23 ° C, 50% humidity) measured.

The minimum, the maximum and the average of five individual measurements are given.

Measured separation forces with the specified measuring method

minimum maximum Average Undamaged reference sample 9 cN / cm 12 cN / cm 11 cN / cm Open side of the release film with pressure roller 18 cN / cm 30 cN / cm 23 cN / cm Covered side of the release film with pressure roller 16 cN / cm 22 cN / cm 19 cN / cm Open side of the release film with substrate electrode 17 cN / cm 24 cN / cm 21 cN / cm Covered side of the release film with substrate electrode 16 cN / cm 20 cN / cm 18 cN / cm

The results show that mainly the maximum values for the separation forces lose weight.

Claims (22)

Process for the production of web-shaped, at least two-layer products, in which a mass emerging from an application device is applied as a layer with the application of electrostatic charges to a web-shaped substrate which is guided on a transport device, and in which the substrate coated with the mass is left before leaving the transport device is electrostatically neutralized,
wherein electrostatic charges are applied to the web-shaped substrate before coating by means of a substrate electrode, so that the substrate is pressed onto the transport device. A method according to claim 1, characterized in that
the application device is designed as a nozzle, in particular a wide slot nozzle, two- or multi-channel nozzle or adapter nozzle. A method according to claim 1 or 2, characterized in that
the transport device is designed as a lay-on roller which is in particular grounded and / or temperature-controlled. Method according to at least one of the preceding claims, characterized in that
the mass is electrostatically charged by means of at least one lay-on electrode, which is located in particular in the region of the lay-up line of the mass layer above the transport device, preferably lay-on roller. Method according to at least one of the preceding claims, characterized in that
two needle electrodes arranged one behind the other in the web direction are used as the lay-on electrode, in which the needles are offset laterally in particular by half a needle spacing. Method according to at least one of the preceding claims, characterized in that
the substrate coated with the mass is electrostatically neutralized by means of at least one counter charge electrode before leaving the transport device, preferably lay-on roller, the counter electrode being located in particular in the region between the support line of the mass layer and the withdrawal line of the coated substrate, above the transport device, preferably lay-on roller. Method according to at least one of the preceding claims, characterized in that
the substrate coated with the mass is kept electrostatically neutral by means of at least one discharge electrode when leaving the transport device, preferably a lay-on roller, the discharge electrode being located in particular in the region of the withdrawal line of the coated substrate above the transport device, preferably a lay-on roller. Method according to at least one of the preceding claims, characterized in that
the substrate is placed on the transport device, preferably lay-on roll, with a pressure roller and / or is removed from the transport device, preferably lay-on roll, with a take-off roll. Method according to at least one of the preceding claims, characterized in that
a screen made of electrically insulating material is attached in the web running direction between the application device and the application electrode. Method according to at least one of the preceding claims, characterized in that
the substrate is electrostatically neutralized before coating. Method according to at least one of the preceding claims, characterized in that
the electrical voltage of the transport device, preferably lay-on roller, is 1 to 40 kV, in particular 2 to 15 kV. Method according to at least one of the preceding claims, characterized in that
the mass on the substrate is crosslinked before leaving the transport device, preferably a lay-on roller, in particular by means of electron beams, UV rays, visible light or a combination thereof and / or thermally. Method according to at least one of the preceding claims, characterized in that
the substrate electrode is formed from one or more individual electrodes which are arranged one behind the other. Method according to at least one of the preceding claims, characterized in that
the substrate electrode is arranged between the application device and a pressure roller for the substrate. Method according to at least one of the preceding claims, characterized in that
instead of a pressure roller, a substrate electrode is arranged in the region above the line of laying the substrate on the transport device. Method according to at least one of the preceding claims, characterized in that
the substrate electrode is subjected to an electrical voltage of the opposite polarity as the support electrode. Method according to at least one of the preceding claims, characterized in that
the substrate is a carrier material for an adhesive tape and / or the mass is an adhesive. Method according to at least one of the preceding claims, characterized in that
the substrate is a release liner for an adhesive tape. Method according to at least one of the preceding claims, characterized in that
the substrate is a preliminary product, consisting of a release liner, adhesive and carrier, for a double-sided adhesive tape and the compound is an adhesive. Method according to at least one of the preceding claims, characterized in that
the substrate consists of one or more layers and / or the coating consists of one or more layers, at least one of the layers being adhesive. Method according to at least one of the preceding claims, characterized in that
the substrate is a release liner and the coating, consisting of a first adhesive, carrier and a second adhesive, is discharged from a three-channel or adapter nozzle. Method according to at least one of the preceding claims, characterized in that
Acrylic, natural rubber, synthetic rubber or EVA adhesive compositions are used as the composition.

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